The purpose of this work is to develop methods and procedures which will enhance the usefulness of fluorescence measurements as applied in biomedical research. Several categories of advances included: 1. Development of a method to study and measure phospholipase activity by release of a fluorescent dye encapsulated in phospholipid vesicles. 2. A detailed study of the fluorescamine reaction for amino acids and proteins and the development of a method to assay proline from its inhibition of the fluorescamine reaction. 3. Investigation of the o-phthaldialdehyde (OPA) fluorogenic reaction for primary amines. The reaction rates, quantum yields, and other parameters were measured. Factors influencing the extent of reaction were elucidated. 4. The use of internal standards in phosphorimetry was investigated in snowy aqueous matrices.